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<meta name="description" content="A traditional tree view using TreeLayout and orthogonal links."/> 
<link rel="stylesheet" href="../assets/css/style.css"/> 
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<title>GoJS Tree View</title>
</head>

<body>
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          <h1 class="mb-0 p-1 ">GoJS</h1>
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    <!-- * * * * * * * * * * * * * -->
    <!-- Start of GoJS sample code -->
    
    <script src="../release/go.js"></script>
    <div class="p-4 w-full">
    <script id="code">
    // use a V figure instead of MinusLine in the TreeExpanderButton
    go.Shape.defineFigureGenerator("ExpandedLine", function(shape, w, h) {
      return new go.Geometry()
            .add(new go.PathFigure(0, 0.25*h, false)
                  .add(new go.PathSegment(go.PathSegment.Line, .5 * w, 0.75*h))
                  .add(new go.PathSegment(go.PathSegment.Line, w, 0.25*h)));
    });

    // use a sideways V figure instead of PlusLine in the TreeExpanderButton
    go.Shape.defineFigureGenerator("CollapsedLine", function(shape, w, h) {
      return new go.Geometry()
            .add(new go.PathFigure(0.25*w, 0, false)
                  .add(new go.PathSegment(go.PathSegment.Line, 0.75*w, .5 * h))
                  .add(new go.PathSegment(go.PathSegment.Line, 0.25*w, h)));
    });

    function init() {
      var $ = go.GraphObject.make;  // for conciseness in defining templates

      myDiagram =
        $(go.Diagram, "myDiagramDiv",
          {
            allowMove: false,
            allowCopy: false,
            allowDelete: false,
            allowHorizontalScroll: false,
            layout:
              $(go.TreeLayout,
                {
                  alignment: go.TreeLayout.AlignmentStart,
                  angle: 0,
                  compaction: go.TreeLayout.CompactionNone,
                  layerSpacing: 16,
                  layerSpacingParentOverlap: 1,
                  nodeIndentPastParent: 1.0,
                  nodeSpacing: 0,
                  setsPortSpot: false,
                  setsChildPortSpot: false
                })
          });

      myDiagram.nodeTemplate =
        $(go.Node,
          { // no Adornment: instead change panel background color by binding to Node.isSelected
            selectionAdorned: false,
            // a custom function to allow expanding/collapsing on double-click
            // this uses similar logic to a TreeExpanderButton
            doubleClick: function(e, node) {
              var cmd = myDiagram.commandHandler;
              if (node.isTreeExpanded) {
                if (!cmd.canCollapseTree(node)) return;
              } else {
                if (!cmd.canExpandTree(node)) return;
              }
              e.handled = true;
              if (node.isTreeExpanded) {
                cmd.collapseTree(node);
              } else {
                cmd.expandTree(node);
              }
            }
          },
          $("TreeExpanderButton",
            { // customize the button's appearance
              "_treeExpandedFigure": "ExpandedLine",
              "_treeCollapsedFigure": "CollapsedLine",
              "ButtonBorder.fill": "whitesmoke",
              "ButtonBorder.stroke": null,
              "_buttonFillOver": "rgba(0,128,255,0.25)",
              "_buttonStrokeOver": null
            }),
          $(go.Panel, "Horizontal",
            { position: new go.Point(18, 0) },
            new go.Binding("background", "isSelected", function(s) { return (s ? "lightblue" : "white"); }).ofObject(),
            $(go.Picture,
              {
                width: 18, height: 18,
                margin: new go.Margin(0, 4, 0, 0),
                imageStretch: go.GraphObject.Uniform
              },
              // bind the picture source on two properties of the Node
              // to display open folder, closed folder, or document
              new go.Binding("source", "isTreeExpanded", imageConverter).ofObject(),
              new go.Binding("source", "isTreeLeaf", imageConverter).ofObject()),
            $(go.TextBlock,
              { font: '9pt Verdana, sans-serif' },
              new go.Binding("text", "key", function(s) { return "item " + s; }))
          )  // end Horizontal Panel
        );  // end Node

      // without lines
      myDiagram.linkTemplate = $(go.Link);

      // // with lines
      // myDiagram.linkTemplate =
      //   $(go.Link,
      //     { selectable: false,
      //       routing: go.Link.Orthogonal,
      //       fromEndSegmentLength: 4,
      //       toEndSegmentLength: 4,
      //       fromSpot: new go.Spot(0.001, 1, 7, 0),
      //       toSpot: go.Spot.Left },
      //     $(go.Shape,
      //       { stroke: 'gray', strokeDashArray: [1,2] }));

      // create a random tree
      var nodeDataArray = [{ key: 0 }];
      var max = 499;
      var count = 0;
      while (count < max) {
        count = makeTree(3, count, max, nodeDataArray, nodeDataArray[0]);
      }
      myDiagram.model = new go.TreeModel(nodeDataArray);
    }

    function makeTree(level, count, max, nodeDataArray, parentdata) {
      var numchildren = Math.floor(Math.random() * 10);
      for (var i = 0; i < numchildren; i++) {
        if (count >= max) return count;
        count++;
        var childdata = { key: count, parent: parentdata.key };
        nodeDataArray.push(childdata);
        if (level > 0 && Math.random() > 0.5) {
          count = makeTree(level - 1, count, max, nodeDataArray, childdata);
        }
      }
      return count;
    }

    // takes a property change on either isTreeLeaf or isTreeExpanded and selects the correct image to use
    function imageConverter(prop, picture) {
      var node = picture.part;
      if (node.isTreeLeaf) {
        return "images/document.svg";
      } else {
        if (node.isTreeExpanded) {
          return "images/openFolder.svg";
        } else {
          return "images/closedFolder.svg";
        }
      }
    }
    window.addEventListener('DOMContentLoaded', init);
  </script>

<div id="sample">
  <div id="myDiagramDiv" style="border: 1px solid black; width: 300px; height: 500px"></div>
  <p>
    This shows how to create a traditional "TreeView" in a <b>GoJS</b> diagram.
    There are 500 nodes in the tree.
  </p>
  <p>
    Look at this page's source code to see how the properties on the <a>TreeLayout</a> are set.
  </p>
  <p>
    The node template makes use of a "TreeExpanderButton" panel to implement the expand/collapse button.
    It also implements a custom doubleClick function to allow nodes to be expanded/collapsed on double-click.
    Lastly, the source of the picture on each node is bound to two different properties, <a>Node.isTreeLeaf</a> and
    <a>Node.isTreeExpanded</a>; the <b>imageConverter</b> function is used to select the correct image
    based on these properties.
  </p>
  <p>There are two link templates in the source code, one which uses no lines, and one which connects the items with dotted lines.</p>
  <p>
    See the <a href="../intro/buttons.html" target="_blank">Intro page on Buttons</a> for more GoJS button information.
    The <a href="triStateCheckBoxTree.html" target="_blank">Tri-state CheckBox Tree</a> sample demonstrates a "tree view" where each item
    has a three-state checkbox.
    The <a href="treeMapper.html" target="_blank">Tree Mapper</a> sample demonstrates how to map (draw associations) between items in two trees.
    The <a href="updateDemo.html" target="_blank">Update Demo</a> sample also uses a "tree view" for its own purposes.
  </p>
  <p>The icons in this sample are from <a href="https://icons8.com/" target = "blank">icons8.com</a></p>
</div>
    </div>
    <!-- * * * * * * * * * * * * * -->
    <!--  End of GoJS sample code  -->
  </div>
</body>
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